1. Field of the Invention
This invention relates to a remote control switch circuit and more particularly to a switch circuit that remotely controls the power supply of an instrument by a low current signal path and provides temporary power after the supply has been disconnected for orderly power down of the instrument.
2. Description of the Prior Art
The power supply of an instrument is typically controlled by a manually operated front panel switch. This switch connects and disconnects lines which carry high input voltages and current through the instrument to the front panel. When the switch is opened, the lines are disconnected and the power is immediately cut off to all circuitry within the instrument.
Although inexpensive and simple in operation, such conventional power switches suffer from several major drawbacks. First, the high input voltages and current which are run through the instrument to the front panel pose a significant hazard to operator safety. Second, the immediate cutoff of power to the instrument can cause the loss of important information that has not been stored by the instrument. Moreover, conventional power switches also lack the capability to permit external control of the instrument by a remote device.